Every icon that I have set a custom icon for are showing the blank paper error. I have custom icons set for all my hard disks and my mojave boot partition. They are set to the pre-Yosemite nice looking HDD icons instead of the new horrible kindergarten icons.
Catalina shows them as the white papers, but all drives that have stock icons show up properly.
The custom icons are stored on the drives where the icons are set though.. If you enable hidden files you'll actually see the image file. So I doubt that's the issue.
The custom icons are stored on the drives where the icons are set though.. If you enable hidden files you'll actually see the image file. So I doubt that's the issue.